document.write( "Question 885190: the sum of the present ages of a father and son is 53 years. four years ago, the father's age was four times the age of the son. find their present ages. \n" ); document.write( "
Algebra.Com's Answer #535162 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
the sum of the present ages of a father and son is 53 years.
\n" ); document.write( "f + s = 53
\n" ); document.write( "f = (53-s); use this from for substitution
\n" ); document.write( ":
\n" ); document.write( "four years ago, the father's age was four times the age of the son.
\n" ); document.write( "f - 4 = 4(s-4)
\n" ); document.write( "f - 4 = 4s - 16
\n" ); document.write( "f = 4s - 16 + 4
\n" ); document.write( "f = 4s - 12
\n" ); document.write( "replace f with (53-s)
\n" ); document.write( "53 - s = 4s - 12
\n" ); document.write( "53 + 12 = 4s + s
\n" ); document.write( "65 = 5s
\n" ); document.write( "s = 65/5
\n" ); document.write( "s = 13 is the son's age
\n" ); document.write( "I'll let you find the father's age, check your solutions in the 2nd statement\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );